1. Field of the Invention
The present invention relates to an organic EL display apparatus having an organic EL device containing a delayed fluorescence material and a soaking member.
2. Description of the Related Art
Recently, research and development of an organic EL display apparatus using an organic EL device have actively been conducted.
The organic EL display apparatus has a plurality of red organic EL devices, green organic EL devices, and blue organic EL devices, each of which independently performs light emission and non-light emission as a pixel to display a full-color image.
The organic EL device has a pair of electrodes and a light-emitting layer that is disposed between the electrodes and formed of an organic compound.
A plurality of wirings are connected to the organic EL device. The wirings include a wiring transmitting gradation information for each wire, a wiring transmitting emission timing, and the like.
Also, a plurality of organic EL devices are connected to one wiring. One of the wirings serves to supply a current, and, when the plurality of organic EL devices are connected to the wiring, a large current flows to the organic EL device close to a power source to generate Joule heat which causes an increase in temperature. Also, depending on the position of the power source, the organic EL device close to the power source receives heat from the power source as compared to the organic EL device distant from the organic EL device. As a result, a temperature difference is caused between the plurality of organic EL devices disposed in a pixel region. Thus, emission luminance is varied between the organic EL devices even when identical information is so supplied as to achieve light emission of identical emission luminance. Therefore, uneven luminance is generated when pixels are compared to one another.
While fluorescence materials and phosphorescence materials have been developed, use of a delayed fluorescence material having high internal quantum efficiency for the organic EL device is disclosed in Japanese Patent Application No. 2004-241374.
Though Japanese Patent Application No. 2004-241374 discloses the organic EL device having the delayed fluorescence material, an organic EL display apparatus provided with red organic EL devices, green organic EL devices, and blue organic EL devices as pixels is not described nor suggested. Also, though the delayed fluorescence material is the one with which strong delayed fluorescence spectrum and phosphorescence spectrum are observed within a range of 520 to 750 nm, the emission wavelength actually shown in drawings has a maximum emission wavelength that is formed of a peak exceeding 550 nm and a peak exceeding 600 nm. In short, the disclosed delayed fluorescence material is not a light-emitting material that is capable of emitting any elementary color such as green and blue in terms of its color purity.